Hydraulic elevator drive and control



Aug. 28, 1951 G. D. PETTE-NGILL ETAL HYDRAULIC ELEVATOR DRIVE AND CONTROL Filed Feb. 1, 1949 INVENTORS George D. fame/7917A and Y Samuel M flew/yer ATTORNEYS Patented Aug. 28, 1951 UNITED STATES EQPAT'ENT' orries f I George, D Pettengill ROL and Samuel viiflejtcher,

Warsaw, N. Y 'assignors to -Warsaw Elevator 00., Warsaw, N. Y.

l Application February 8 Claims.

This inventionrelates to improvements in electrically powered hydraulic elevator systems the term hydraulic elevator as'used herein being intended to relate to apas'senger and/or freight carrying elevator traveling'within' a hatchwayprovide an improved type of hydraulic elevator.

drive and braking mechanism embodying an improved motor and pirmp interconnection means and an improved motor-pump electrical control system which is of such character as to provide overall improvedwlevatorcar acceleration and deceleration characteristics as well as up and down speed control, while employing the most economical type electric motor and avoiding need of complicatedand expensivemotor speed control apparatus.

Another object of the invention is" to provide an improved hydraulic elevator drive mechanism which provides a smoother 'startingoperation while imposing'lower inrushcurrents on the driving motorwindings.

Another object of the invention is to" provide a new and improved hydraulic elevator drive mechanism which supplies a novel and improved braking action for stopping the elevator car. Another object of the invention is to provide a unique application and development of electric braking principles in hydraulic elevator drive devices.

Another objector-the invention is to" provide a unique and improved hydraulic elevator driving mechanism which gives improved up and down speed control and performance.

Another object of the invention is to" provide an improved hydraulic elevator driving and braking system which'makes it possible to obtain automatic levelling of the car through 'means of a minimum of -control arrangements.

Another object of the invention is to provide a new and improved driving motor-to-pump coupling arrangement in hydraulic elevator drives and the like, whereby-to obtain smoother starting and stopping of the elevator car. 7

Other objects and advantages of the invention will appear from the specification hereinafter.

In order to attain the objects and advantages set forth hereinabove the invention contemplates an elevator drive u'nit'bomprising a relatively 1,'-"1e49;="seria1Nomiaeee V reversible positive f'displacement. pump: supply-ing vfiu'id'fi'om areservoir tothei'elevator cylinder; a fiflywheel; a holdingiivalve intthe line between the pump and the cylinder fandwhere necessary, asuitable' speed reduction gear'unit interconheating the driven portion of: the torque. transmitter and the. pump. Within'the concept: of f the present invention it .isessential that the" motor be" adaptable: to. .A', C; plugging service; that is, adaptable to .sudden reversal as to phase: re- "-1ation,"an'd that the 'torquettransmitter beiadapted to""slipwhile"the'i-rriotor istfpluggedwor when coming up to speed so. as to avoid excessive rush of' 'starting i'curre'nts'ithroughtthel motor windings, and to av'oidtuncomfortable deceleration adc'elera'tion' of tlie elevator car. It is also essential that the' torque :transmitterbe of. such '-'n'ature as to 'impose"high"drag"forces from the -plugged' motor upon the pump :system during the i'nitialhighspeed stage of elevator car'decelera'tion preliminaryito a stopping operationg'and it is further ess'ential;"for'the"purposes ofzthe in'V'entiorr; that. the" torque: transmitter be' 'de- =signedto impose relatively low drag forces upon the pump during the later stages of 'elevator' car -de'celeration;incidental to 'a'stopping operation. The" iri'v ention contemplates a' novel" motor torque control system? which. obtains final stopping of theelevator' car through electrica'l brak- 3@ ing of the motorwhich is'connectedtoithe pump;therebyrequiring only a minimum-duty hydraulic" line valve device for iholding-"'purposes only.' The'torque' "transmitter may be of some suitable traction type ,such' as for example 5' a "fiuid coupling deviceen' ploying the liy'drol'cinetie princi le or a 'hy'dfaulic system of the torque converten typa or" an electromagnetic clutch, or a suitabl e"Variableslipmechanical -'-c'lut ch,' or the' l'ike Hiiviiever; '-I presently prefer "}toerfiploy ior th purpose a mismana m- {viceibedause of ars mechanical Simplicity and '-i"-uggedness an'd eedaam sna ease of operations, s well asfbecause of -its erational' charactertil . .j ei r insf'n vit ith d' a gr e i fi ure: is I acia a r mat repr' e ntation 1 of 'fan'fele'vator "fdriving andbralging d c trol mechanismfemo the elevator car is n'iou iiiow w i h-1s ff though the elevator e it Willbe understood of he" of any suitable" type as Will 11 v to travel in its hatchway upon suitableg'mdes,

' sequence control switch 60.

all in accord with conventional elevator principles. A conduit I5 connects at one end into the cylinder I4 and at its opposite end into the discharge port of a directionally reversible positive displacement type pump I6. The intake port of the pump I6 is connected to a conduit I8 leading into afluid reservoir 20, and a bypass conduit 2| leads from the conduit I5 around the pump I6 into the reservoir. The conduit 2I includes a pressure relief valve 22, and a holding valve 23 is provided in the line of the conduit l5 ahead of the take-ofl" to the conduit 2I. The

impeller of the pump I6 is connected to a shaft' 24 on which is mounted a flywheel and which in turn is keyed to the driven element of a traction coupling device which is illustrated generally at 25. The driving element of the traction coupling 25 is fixed to the armature shaft 26 of the elevator driving motor 30. The motor 30 is illustrated herein to be of the three-phase single speed A. C. type, and the valve 23 is arranged to be electromagnetically actuated by 1 means of a solenoid 3I which is normally springbiased into valve-closed position but energized through means of conductors 3233 leading from the motor terminals into valve open position whenever the motor 30 is energized.

In the drawing the circuits carrying power to the'motor 30 are shown in heavy lines, commencing with supply mains 34-3536 and thence leading through circuit controlled relays, the operation of which will be explained fully hereinafter. It will of course be understood that the invention is applicable to various types of driving motors and control systems, and that the drawing herein purposely illustrates only a relatively simple or basic motor control system providing minimum elevator control features. Thus, the drawing herein shows a control system embodying the usual hatchway door contact a switches; an elevator car gate switch; normal limit switches; terminal limit switches; a car safety switch, and the usual manual control switch in the elevator car. However, further accessory features may be readily added to the control system shown in the drawing herein as will be readily understood by those skilled in the art, so as to include for example automatic operation from hall buttons, automatic leveling, automatic door operation, and so on.

Referring again to the drawing; whereas the power circuits are shown in heavy lines, the control circuits are shown in lighter lines, and the manual car controlswitch is indicated at 40 as comprising a lever pivotally mounted on the elevator car wall. The lever 40 carries a conducting segment 42 which, when the lever is in its neutral position interconnects contact terminals 44-46-48 of the control circuit. Commencing at the lower left hand corner of the drawing, it will be seen that a control circuit feed is picked up from supply main 35 by a control conductor 50 which includes in series therewith an appropriate number of hatchway door contact switches, depending upon the number of doors in the hatchway. In the drawing, for purposes of illustration, it is indicated that there are three doors in the hatchway equipped with door contact switches, as indicated at 5253-54, respectively. The conductor 50 also includes the elevator car gate contact switch 55 and then terminates at a normally open terminal 56 of a The switch 60 is actuated by a relay coil 62 as will be explained hereinafter. The second control circuit feed originates at' 4 I supply main 36 and leads therefrom through conductor 64 and thence through the upper terminal limit switch 66 and thence through the lower terminal limit switch 68 and thence through the car safety switch 10 to the controller terminal contact 48. The contact terminals 46-48 of the controller switch are interconnected by a conductor I2, and hence the second control circuit continues on through terminal 46 and through conductor I4 to a second normally open contact I6 of the sequence -relay switch 69. Another conductor 18 leads from the contact I6 to the terminal armature I9 of a twoway normally open motion responsive switch 80. The armature of the switch 80 is connected such as by means of a friction coupling device SI of the fluid coupling type to a shaft 82 which is in turn geared to the pump drive shaft 24 as by means of a sprocket-chain system 84. Hence, whenever the pump drive shaft is rotating in one direction the armature of the switch 80 will be thrown over against one of either of the contact terminals 86-88 of the switch; while upon reversal of the direction of shaft rotation the switch armature will be thrown over against the other contact terminal of the switch. However, when the pump drive shaft is stopped the armature of the switch 80 moves to its neutral or noncontacting position, as under the influence of spring means 89.

Thus, it will be seen that when the car controller. 4G is in its neutral position, as shown in the drawing, the segment 42 thereof interconnects the contacts 444648 thereby creating a control feed from either terminal 46 or 48 to terminal 44 which is connected through conductor 9G to the relay coil 62 of the sequence control switch 60. Thus, when all of the hatchway doors and the elevator gate are closed (with the car controller in neutral position) the relay coil 62 is energized and lifts the switch device 60 so as 1 to bridge the contacts thereof. By means of the 1 tact lower pair of contacts of the switch the circuit of the relaycoil 62 remains energized and the relay switch holds itself closed, while the bridging of the upper pair of contacts of the relay switch provides feed for the motor control relay coils 92-94-96.

Thus, if the car controller handle 40 is moved over to the up position the segment 42 will clear the contacts 44--46 and will interconnect the contact 48 with another contact I00, thereby providing a closed circuit from terminal I00 through conductor I02, and thence through the upper normal limit switch I04 and thence to con- I 06 of a normally closed relay switch I08 and thence through the relay coil 92 of a relay switch III]. This will energize the coil 92, thereby lifting the relay switch II 0, whereupon the upper power control contacts thereof will close. At the same time the auxiliary contacts at the bottom of the switch I ID will close, providing a closed circuit to the relay coil 96 on the relay switch II2..- This lifts the switch II2, whereupon it will be seen that the power control contacts of motor torque being transmitted through the fluid coupling 25. The fluid coupling device 25 thereupon operates to provide a particularly soft acceleration effect becauseof its inherent tend- .1 .l-asespeo ,encyto slip at slow. speedsand to gradually. in-

....-.crease in torque. transmitting efliciency assthe speedincreases.

is -..energization of.the motor. 30 through conductors As explainedrhereinabove, the solenoid device automatically energized coincidentally with- ...32-.-33 leadingfromtwo of. themotor terminals so. as to, openthe valve 23 whenever .themotor. 30

. is energized, .whenever the powerto the. motor isinterruptedg teed throughthe segmentJlZ. between -.the con-" tacts 48.1lll3 istherebyinterrupted, and the.cir-

while the valve automatically .closes thereby holding .the .elevator.

. The upward .travel of .the .-elevator. .carmay, of

from the..car,.such. as

turned by the operator to its neutralpositiomthe cuitincluding the coil) 92.in.the..up. travel relay unit is now deenergized. .Momentarily, however,

. ,the inertia of the .carand thedrive mechanism will continue the upward travel of the car, and" therefore the armature of the traction switch 80 is still biased tokeep the up travel contacts closed. Thus, the feed from the controller contact 46 forms a, closed circuit throughthe conductors ll-.48 and the traction switchBiJ and the conductor, I26 and the contact 12% of the relay .switchllllh As the switch .lltidrops, due to deabove, the

, thereupon completed-through switch contact 128? conductor I39, controllercontactlBZ, and thence through the lowernormal limit switch [34, and

energization of the coil 92 as explained hereincircuitthrough the. contact 1.25 is thenback throughconductor. l36. through. ,con-

tacts 138-439 of the relay switch I [0, to the.coil

, ,Sdof the down control relay switch 1.08, andthence through contacts 51401-56. of theswitch 60 and thence throughconductor 59 to the. supmain line conductor switch ply main 35.

- Thus, the down controlrelay. switchJUB and the thereby completing a three-phase power supply to the motor 30, but in reverse phase relationship to the direction of theprevious operation of the motor. Themotor, is,, thereby plugged or reversed, and drags upon the pump drive meohanism and its flywheel to decelerate the latter in the manner of a braking device; ,the traction coupling device 25 permitting varying rates of slip between the motor and the pump, depending upon the relative speeds thereof.

It is with respect to this braking performance of the motor .30 duringdeceleration of the elevator car travel that the novel torque transmitting characteristics of the traction coupling device, such as for example of the so-called fluid coupling type, become manifest and provide an improved electrical braking or plugging performance when using a motor of the relatively economical single speed A. C. type. For example, when the controller is moved to neutral position the driving mechanism is at first traveling at relatively high speed, and the tendency of the pump end of the drive mechanism to overrun the motor end of the mechanism is at first strenuously resisted because of the nature of the operation of the fluid coupling device at high speeds. Thus, at this stage the motor imposes a high degree of drag upon the drive mechanism, thereby tending to quickly brake the car travel. However, as the rate of car travel is reduced, the coupling zdi becomestless efiicient. as a torquev transmitter,

;and a;rprogressively;softeningirdragging. efiect is supplied by the. motor-to .the.pump, with the re- .sultithat,as the;elevator.car slows down and appreaches the stop..the=..deceleration rate smooths -.of, rthereby avoidingrviolent deceleration shock ill-,Qonnectionwith thestopping operation.

When the pump is brought to;rest, the traction .switchao, will open, thereby interrupting the cir- .cuittto thecontact, .106 andthe circuit to the re- ,-lay .switch,coil 94, permitting the switchglllfl to .drop. .rfIhis-interrupts thepower supply to the ,motorand to. the solenoid ,valve -23, whereupon Lhelatter. isclosed. to hold the. elevator. carat lfdrest.

, ltwillbeappreciatedthat if, instead of manual .-:.'.I8turn of the, controller to neutral position-asexplai,ned hereinabove, the elevator car is permitted to-rise until thecar-cam opens the upper normal limit switchplM, the vcircuits to the coil 92 of the Qiswitch ,1 it will. ,be interrupted; and that, the switch; 80 will thereupon assume control of the system to cause reversal of the motor-soasto -.eff ect the-braking action explained hereinabove the elevator car withuthe and V to finally stop holding valve 23 applied.

. Downward car travel control is effected by the mechanism illustratedupon manual manipulation :of the controller 40 into its .down positionas 9..

shown inthe drawmg, whereupon the control circuits are completed to energize the down re- Qlay andthe. main lineswitch H2 to complete a a three-phase power-supply to the motor inreversed phase relation. The switch 89 then closes inthe-down direction upon starting; of the elevator travel upon centering of the car control handle ;40, or opening of the lower normal limit switch I34, the relays lflB-l I2 will be deenergized, whereupon control circuit feed will be esto the coil 92 of in turn energize ;.to. be pluggedf thereby braked as explained -hereinabove until H2 are both liited,

switchflll assumes its neutral position. Thecontablished through switch .80 and conductor 145 the up relay H0, which will relay H2 and cause the motor The elevator mechanism will be it comestorest at which time the armature of trol circuit feed is thenbrolren to the up relrlay H0, which thenfalls out and deenergizes the motor 30 and causes the valve 23 to @be set.

' Thus, it will be understood that it is a particular feature and advantage of: the invention that acceleration of theelevatorcar travel is acquired through a traction-type coupling which prevents violent acceleration effects, and that brakingof .the car travel is acquired by plugging the single speed A. C; motorand transmittingthe drag therefrom to the: elevator pump drive shaft through the traction coupling device which-delivers in improved manner a counter-torque operating to retard and stop the car. Thus, a nearly constant rate of deceleration is obtained and no violent deceleration effects are experienced, and the car comes to a soft stop because of the braking characteristics of the plugged motor operating in cooperation with the novel coupling element of the driving system.

What is claimed is:

1. In a hydraulic elevator drive and braking control system, a directionally reversible alternating current electric motor, a directionally reversible positive displacement pump, a fluid conduit interconnecting said pump and the cylinder of said hydraulic elevator, a fluid coupling device interconnecting the drive shaft of said motor and said pump, and a power supply control system for' said motor including manualswitch means operable to cause energization of said motor, switch means operable to reverse said motor to impose a counter-torque through said coupling device to 1 halt the elevator travel, and means operable automatically upon halting of said travel to deenergize said motor. v

2. In combination, a hydraulic elevator cylinder, a directionally reversible positive displacement pump in operative connectionwith said cylinder, a reversible alternating current electric motor, a traction type coupling device interconnecting the drive shaft of said motor and said pump, and a power supply control system for said motor including. manual switch means operable to start said motor to run in either direction and operable to reverse the phase relation of said motor while running to impose a counter-torque through said traction coupling device to halt the elevator travel, and switch means operable auto matically upon halting of said travel to deenergize said motor.

3. In a hydraulic elevator drive and braking control system, a reversible alternating current electric motor, an elevator driving pump, a fluid coupling device interconnecting the drive shaft of said motor and said pump, and a power supply control system for said motor including manual switch means operable to cause energization of said motor, switch means operable to reverse said motor when running to impose a counter-torque through said coupling device to halt the elevator travel, and means operable automatically upon halting of said travel to deenergize said motor.

4. In a hydraulic drive and braking system for elevators, a reversible alternating current motor,

an elevator drive pump, a traction type coupling device interconnecting the drive shaft of said motor and said elevator drive pump, a conduit connecting said pump to the elevator cylinder, a valve in the line of said conduit, and a power supply control system for said motor including switch means operable to cause energization of said motor, switch means operable to reverse said motor when running to impose acounter-torque through said traction coupling device to brake the elevator travel, and means operable automatically upon halting of said travel to deenergize said motor and to close said valve.

5. In a hydraulic elevator drive and braking control system, a reversible alternating current electric motor, an elevator drive pump of positive displacement type, a fluid torque converter interconnecting the drive shaft of said motor and said elevator drive pump, and a power supply control system for said motor including manual switch means operable to cause energization of said motor, switch means operable to reverse said motor to impose a counter-torque through said converter to halt the elevator travel, and means operable automatically upon halting of said travel to deenergize said motor.

6. In combination, a hydraulic elevator pump of positive'displ'acement type, a reversible alternating current electric motor, a torque converter coupling device interconnecting the drive shaft of said motor and said pump for actuating the latter, and a power supply control system for said motor including manual switch means operable to start said motor to run in either direction and operable to reverse the phase relation of said motor while running to impose a counter-torque through said traction coupling device to halt the elevator travel, and motion responsive switch -means operable automatically upon halting of said travel to operate to cause said motor.

'7. In a hydraulic elevator drive and braking control system, a reversible alternating current electric motor, an elevator drive pump of positive displacement type, a fluid torque converter interconnecting the drive shaft of said motor and said elevator drive pump, and a power supply control system for said motor including manual switch means operable to cause energization of said motor, switch means operable to reverse the phase relation of said motor when running to impose a counter-torque through said converter to halt the elevator travel, and means operable automatically upon halting of said travel to deenergize said motor.

8. In a hydraulic drive and braking system for elevators, a reversible alternating current motor, an elevator drive pump of positive displacement type, a fluid torque converter device interconnecting the drive shaft of said motor and said elevator drive pump, and a power supply control system for said motor including switch means operable to cause energization of said motor, switch means operable to reverse the phase relation of said motor when running to impose a counter-torque through said fluid torque converter to brake the elevator travel, and means operable automatically upon halting of said travel to deenergize said motor.

deenergization of GEORGE D. PETTENGILL. SAMUEL V. FLETCHER REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

